DNA, Epigenetics and bloodlines ending…
For more information on Untenable: Our Fragile Preservation check out the production’s official page.
Throughout Western history, people have believed that fate and heredity can intertwine in uncanny ways. Ancient mythmakers, theologians, and even early scientists spun tales in which family secrets and sins echoed down generations. In the Hebrew Bible, for example, God warns that “the iniquities of the fathers are visited upon the sons and daughters—unto the third and fourth generation”[1]. The Greeks dramatized such themes with chilling vividness: when the servant Myrtilus died under Pelops’ hand, he cursed “Pelops and his line,” dooming the House of Atreus to one atrocity after another[2]. Over time murder, revenge, and even cannibalism all marked that bloodline—until at last Orestes, haunted by guilt, slew his mother and finally broke the cycle: Athena declared that “no descendant of Atreus… would ever again be driven into evil by the irresistible power of the past”[3]. These stories, from Exodus to Aeschylus, rooted moral teaching in family fate.
Yet similar ideas reappear in science’s more recent past. By the early 20th century, the new fields of genetics and eugenics began to cast heredity in quasi-mythic terms. Mendel’s laws promised a precise inheritance of traits, and pioneers like Francis Galton argued that society could be “purified” by selective breeding. Leading eugenicists at Cold Spring Harbor literally drew pedigrees to prove social ills were in the blood. One infamous example is the Kallikak family study: psychologist Henry Goddard claimed a Quaker soldier’s drunken dalliance spawned a “feeble-minded” lineage, ending in a tragic daughter dubbed “Deborah”[4]. In Goddard’s portrait, the legitimate branch of the Kallikak family was virtuous; the illegitimate side produced criminals and defectives. The resulting pedigree was pure propaganda—the “barmaid” mother never existed—but for decades it was taught as fact, a cautionary tale of inherited genetic taint[4][5].
- Myths and Curses: Traditional folklore is full of ancestral woes. Biblical law (“visiting the iniquity of the fathers”[1]), Arthurian legends (the ban on Mordred’s child), and even modern thrillers (the idea of an occult Jesus bloodline) play on the idea that origins define destiny. In Egyptology, curses on tombs are legendary—and Victorian journalists popularized the “mummy’s curse” trope after Tutankhamun’s tomb was found. In reality, a BMJ study found no unusual mortality among those who entered King Tut’s tomb (they lived to ~70 on average)[6]. Scholars trace the curse story to 19th-century fiction: women writers cast tomb-robbing as a sexualized sin, with ghoulish payback[7][8]. Modern audiences know the trope from The Mummy films, but it began as a metaphor for colonial plunder, not genes.
- Pedigree Panic: In history’s classroom, genetics and prejudice often marched together. As the Guardian reports, early 20th-century eugenicists openly embraced racial fear: Cold Spring Harbor’s Eugenics Record Office warned of a “great replacement” of virtuous stock by “undesirable people” who would “spread inferior genes” and erase “the ruling classes”[9]. The Nazis took up these ideas with zeal. A 1935 propaganda film Das Erbe (“The Inheritance”) showed a fanciful “Kallikak” family, demonizing disability and celebrating sterilization. Its climax was Hitler’s own pledge that the “physically and mentally” fit would procreate, reinforcing the myth of a sacred Aryan bloodline[10]. Even today, conspiracy culture peddles similar fantasies. Fringe theorist David Icke claims “the same interconnecting bloodlines have controlled the planet for thousands of years,” invoking an ancient secret cabal[11]—a notion critics note eerily echoes the medieval European “blood libel” myth of conspiratorial Jewish world dominion[12]. In short, the very language of “bloodline” and inheritance has often been wielded for dark agendas.
The Epigenetic Revolution
Amid these legends, scientists have quietly probed how our bodies really pass information to offspring. The discovery of DNA’s double helix (1953) and genes’ chemical basis set the stage, but it became clear that genes are not destiny. Over the past few decades the field of epigenetics has emerged to explain how environment and experience can influence gene activity. As Carl Zimmer (writing in The Atlantic) explained, identical organisms can behave differently if their DNA is chemically tagged. In a famous 1990s experiment, a toadflax plant variant called Peloria had the same genetic sequence as normal toadflax, but a gene critical for flower symmetry was heavily methylated, silencing it and producing radial flowers. “The gene is identical…The difference was not in their DNA but around it,” Zimmer notes—epigenetic marks, not mutations[13]. In other words, genes provide the script, but epigenetic chemistry (like DNA methylation or histone changes) helps write the final scene.
Epigenetics thus allows some parental experiences to influence offspring. In labs, stressed or malnourished animals often sire children with unexpected traits. For example, mice taught to fear a smell will have progeny that also fear it, even without direct exposure[14]. Human studies find tantalizing hints too: one famous analysis looked at Union Army POWs from the 1860s. The sons of soldiers who had endured the brutal Andersonville camps died younger on average than sons of other veterans—a pattern the authors argued could only be explained by something “working through epigenetics,” since the sons themselves weren’t at war[15]. The researchers controlled for social class and other factors, and concluded the trauma (or malnutrition) “moves the machinery to put down…epigenetic markers”[15][16].
Other human findings have been advanced as transgenerational epigenetics. The Dutch “Hunger Winter” of 1944–45 left grand experiments: children conceived in famine were more prone to heart disease and obesity later, and intriguingly the grandchildren of malnourished grandfathers showed increased fat levels[17]. A 2014 study reported that sons (but not daughters) of fathers who started smoking before puberty were heavier than those whose fathers started later[18]. And Rachel Yehuda’s team found Holocaust survivors and their children shared epigenetic marks on a stress-related gene, implying trauma “was passed onto their offspring”[19]. In each case, the story seems to be written in chemical tags rather than in DNA letters.
However, even many researchers remain cautious. Bernhard Horsthemke, writing in Nature Communications, stresses that although epigenetic marks can be “written down” in a cell, they “cannot easily be transmitted” across generations[20]. In mammals there is a powerful reset: sperm and eggs largely wipe clean these marks during development. Only a few lucky loci might escape the “power-wash” of fertilization. Horsthemke notes that the idea of inherited trauma is tantalizing but often doubtful: “Lamarck has never been dead” is a catchphrase in the epigenetics literature[21], but almost all known transgenerational effects come from fast-breeding lab creatures. As he and others point out, the strongest proof of transgenerational epigenetics remains in worms, flies and rodents—not humans. As Nautilus magazine dryly observed, “the most compelling evidence for transgenerational epigenetics is in rodents, not humans”[22]. And epidemiologist George Davey Smith warns that epigenetics can become “the currently fashionable response to any question to which you do not know the answer”[23].
Indeed, some human studies have fizzled under scrutiny. The Civil War study’s epigenetic interpretation was ultimately “more like conjecture…or a process of elimination,” its authors admitted, since they only had demographic data[24]. Others caution that when subjects are followed into deeper generations, the strongest signals often fade or invert. The Swedish Överkalix studies of 19th-century harvests suggest that mild famine in adolescence—not abundant food—may have benefited grandchildren’s health, hinting at complex adaptive responses rather than simple curses[25]. And critics of the Holocaust findings noted the tiny sample and lack of deeper-generation data[26]. In short, while the epigenetics story is rich with possibilities, many details remain unresolved.
Genes Among the Living
Meanwhile, the notion of a sacred “bloodline” has also collided with genetic reality. Modern genomics shows that lineages intermix to an extent that would astonish ancient storytellers. Every person carries not a private ancestry but a vast tangle of forebears. Geneticist Adam Rutherford observes that “literally everyone with European ancestry is directly descended from Charlemagne”[27]—hardly a surprise once one understands pedigree math. By about 33 generations ago (roughly 800–1000 CE), each of us theoretically has over eight billion ancestor slots—more than the world population at the time[28]. The paradox is resolved by overlap: the same individual frequently appears multiple times in one’s family tree. In fact, in modeling, scholars find the most recent common ancestor of all living humans likely lived just a few thousand years ago[29]. In Rutherford’s words, these insights “absolutely, categorically demolish[] the idea of lineage purity”[30]. We are far closer kin to one another than folklore or ethnic myths would suggest.
Genetic genealogy adds its own twists. DNA testing services have revealed countless surprising family secrets, often sending individuals to sleuth out their roots online. Sometimes these quests stumble onto tragedies. Sarah Zhang recently told the story of a man who discovered through genetic analysis that his birth parents were first-degree relatives, meaning he was unknowingly the product of incest[31]. Studies of large DNA databases confirm that such cases are much more common than expected: about 1 in 7,000 Britons in one genetic biobank study turned out to have parents who were close relatives[32]—”way, way more than many people would ever imagine,” the lead geneticist said. Each such finding is a human drama, but it also underscores that real family trees often have hidden branches.
DNA revelations can also upend long-cherished pedigrees. Consider royal or noble lines: a genetic study famously showed that the infamous “Princes in the Tower” of Tudor legend were likely not the true heirs of Edward IV. In broader terms, modern pedigrees have collapsed many national myths. Researchers now believe that nearly everyone alive today has been a direct ancestor of every generation of Europeans past. Susanna Manrubia’s work on genetic “isopoints” finds that all Jews of Ashkenazi and Sephardic heritage share common ancestors expelled from Spain in 1492[33]. Put simply, if you’re alive now, your ancestors were likely present at every major historical moment.
Magic, Medicine, or Market?
This collision of myth and molecular biology raises profound questions. Did our ancestors’ sufferings imprint on our cells? Is that ancestral guilt or trauma hidden in our genes? Such ideas have mesmerized novelists, therapists, and yes, some philosophers. One therapist quips to her patients, “your family tree is rooted in Hollywood.” Epigenetics briefly gave new currency to the trope of inherited fate, even as the science wades carefully. As Horsthemke notes, epigenetics deals only with potentially heritable gene-control states, and proving any effect in humans is exceptionally hard[34]. Nonetheless, examples like famine exposure or early parental stress seem to work through “soft inheritance,” at least in part.
To the casual reader, these findings can sound like validation of the old idea that our ancestors’ choices or misfortunes can “scar” our blood. In policy circles, too, there is unease. If trauma or toxins leave lasting marks, might society owe reparations to descendants? Should public health aggressively target pregnant women or even young children to avert epigenetic tolls? These questions echo earlier utopias of genetic “improvement.” Today’s fertility market offers up preimplantation genetic diagnosis and even non-disease editing. In 2018, a Chinese scientist provoked outrage by creating twin girls with CRISPR tweaks (a violation of international norms). That scandal sparked calls for global bans. By 2025, prominent figures like biotech entrepreneur Cathy Tie (dubbed “Biotech Barbie”) have argued that germline editing might be reconsidered—igniting debate once more[35]. A recent panel reminded the world that even if gene editing could eliminate disease, it remains “too risky” to use in embryos destined for birth[35].
The irony is that modern genetics often undermines, not justifies, bloodline mysticism. Policing “pure” lineages is biologically absurd. A radical example: a 2020 Atlantic investigation into DNA parentage found that Amerasians (children fathered by U.S. servicemen in Vietnam) were far more common than expected—on the order of one in ten Vietnamese women had American paternity. That erased decades of assumption about the “eroded” American bloodline there, replacing myth with numbers (the study used odds and DNA to reconstruct population ancestry). Similar stories abound with ancestry testing: once majestic family myths (Viking forebears, or concealed Native ancestors) often turn out to be broad mixtures of many peoples.
Culturally, the promise and peril of epigenetics has given rise to new narratives—some helpful, some unmoored. Therapists sometimes frame psychological issues as “intergenerational trauma” carried in clients’ bodies. Wellness influencers tout lifestyle changes to “rewire your epigenome,” suggesting we are freer from genetics than ever. At the same time, some charlatans conflate epigenetics with reincarnation or karma: they claim trauma is literally encoded in our DNA or the DNA of our descendants and must be “cleared” through mystic rituals. Scientists cringe at such things. Lisa M. Jorgenson, a prominent skeptic, warns that such conflations risk turning a rigorous field into fertile ground for pseudoscience: “suggesting there is genetic memory can quickly slide into saying there is reincarnation”—something for which there is no evidence.
Meanwhile, politics around “blood” have only grown more charged. The racist Great Replacement theory uses pseudo-genetic rhetoric to stoke fear about immigration. Framers like France’s national origin laws of the 20th century explicitly drew on eugenics to decide who was of “good stock.” These ideas ebb and flow with the public mood. In reaction, many people rightly recoil from any talk of “bloodlines”—associating it with the worst of human history. Yet ironically, modern genetics also demolishes that very terror: global DNA evidence shows that we all share ancestors so recently that old racial or religious boundaries have no genetic insulation. In the end, genes show that the “pure” lineage fantasy is exactly that—a fantasy.
So what do we make of the grand motif? Bloodlines that “end” are a literary trope, a political scare, and sometimes a scientific question all at once. Ancient myths warned that the sins of Pelops could poison his descendants; modern studies suggest extreme events might tweak some metabolic or stress-related genes—but also that life has ways of resetting or compensating. The world has witnessed true catastrophes of bloodline: a Siberian plague that wiped out entire clans, or dynasties of rulers who died childless. But those dramas were driven by history as much as by biology. Biology tells us: more often than not, the ancestral tree forks and flourishes in unpredictable ways. In genealogical time, every bloodline merges into the next.
Ultimately, the story of DNA and epigenetics is still being written. It’s a tale of promise—the hope that perhaps we can heal generational wounds—and a tale of caution, reminding us how easily stories outpace solid proof. Western literature and lore may obsess over hidden inheritances, but modern science teaches humility: our genomes have few secrets that nature doesn’t eventually rewrite. As one researcher quipped about the Civil War data, the notion of “epigenetic inheritance” is optimistic—it allows for reversibility (better maternal nutrition, even before birth) and is not deterministic[36]. Despite myths that ancestors’ fates were etched in our blood, the evidence suggests we are neither doomed nor magically guaranteed by our forebears. Genes may bear scars of history, but they also carry the blueprint for change.
Also, don’t forget to check out “Untenable: Our Fragile Preservation” Behind The Screenplay page for more information on the writing inspiration and process.
